MEFA4 VERSIONS

Version 0.2-4 -- August 23, 2011
    * groupMeans: NA handling changed, mean is calculated
      as dividing by the non NA values when collapsing.

Version 0.2-3 -- July 9, 2011
    * packageStartupMessage used in zzz.R .onAttach
    * Typos fixed in vignette and help pages.
    * 1x1 dim issues fixed again using drop=FALSE
      at many places (Mefa, <-, [, mbind).
    * typo corrected in mbind for Mefa objects that
      left TAXAPART temp variable in result.
    * samp/taxa table handling in mbind for Mefa objects
      is revised, not using default merge(..., all=TRUE).
    * Xtab: lhs must be numeric.

Version 0.2-2 -- May 13, 2011
    * Allowing for 0 and 1 row/col Mefa objects ('xtab<-' and '[').
    * nonDuplicated finds y in data frame and patent frame first.

Version 0.2-1 -- February 14, 2011
    * Melt function added to reverse side effects of Xtab.
    * Docs for Melt added (Rd, tests, vignette).

Version 0.2-0 -- February 7, 2011
    * First public CRAN release.

Version 0.1-2 -- January 26, 2011
    * nonDuplicated function added.
    * segmented Xtab output implemnted
      as list of sparse matrices.

Version 0.1-1 -- January 25, 2011
    * S4 classes working properly.
    * /tests dir added to pkg tree.
    * Xtab class is redundant, 
      use dgCMatrix class instead.
    * A vignette with design decisions
      added, it also has the performance
      comparison.
    * mbind method for binding matrices
      added with a 'left join' implementation.
    * Rd files added, needs proofreading.

Version 0.1-0 -- January 20, 2011
    * Start development for S4 classes.